The export of cryptography is the transfer from one country to another of devices and technology related to cryptography.
In the early days of the Cold War, the U.S. and its allies developed an elaborate series of export control regulations designed to prevent a wide range of Western technology from falling into the hands of others, particularly the Eastern bloc. All export of technology classed as 'critical' required a license. CoCom was organized to coordinate Western export controls.
Currently, many countries, notably those participating in the Wassenaar Arrangement, have similar restrictions.